Mario Kart 8 enjoyed a great attach rate with shipments of 2.82 million by the end of June, but the vast majority of its success can be attributed to existing Wii U owners and not new buyers. Nintendo shipped 510,000 units of its home console across April to June, a quarter in which the company endured a 9.924 billion yen net loss, which converts to $97.2 million.

The systems's total shipments as of June 30 rose to 6.68 million; Nintendo still expects to hit its target of 3.6 million units across the fiscal year, which would take the console to 9.77 million by March 2015. The company admitted in May the Wii U "still faces a challenging sales situation," and it will look to build off the success of Mario Kart 8 with the launch of Super Smash Bros. and its set of Amiibo figurines this fall.

Gallery|11 Photos

Mario Kart 8 (4/2/14)

Meanwhile, the success of Mario Kart 8 highlights what was otherwise a quiet quarter for the Wii U. The game represented 64 percent of the 4.39 million software shipments across the three months, with 80 percent of the racer's uptake coming from outside of Japan.

The picture remains much rosier for Nintendo's handheld. The company shipped 820,000 3DS units across April to June, taking the system's total figures to over 44 million. However, the quarterly results present a significant drop from 1.4 million shipped the previous year, though sales then were likely boosted by the Western launch of Animal Crossing: New Leaf.

While neither Kirby: Triple Deluxe nor Tomodachi Life hit the million mark in Q1, Nintendo cited both games as gaining "wide popularity." Looking ahead, Nintendo said it expects to continue producing "robust" profits from the system with the upcoming Pokemon Sapphire and Ruby remakes, as well as Super Smash Bros. in October.